When the network requests look up the certificate revocation list for each assembly that native image generation (NGen) compiles to native code, each request must time out before the installation continues.

To resolve this issue, disable the Check for publisher’s certificate revocation security option in Internet Explorer. To do this, follow these steps:

Under the Security section, clear the Check for publisher's certificate revocation check box.

Click OK.

We recommend that you clear this security option in Internet Explorer if the computer is in a tightly controlled environment. After you install this update, re-enable the Check for publisher’s certificate revocation security option.

Update issue on computers that have customized Outlook Web App files

Important Before you apply the update rollup, we recommend that you make a backup copy of any customized Outlook Web App files. For more information about how to customize Outlook Web App, visit the following Microsoft website:

When you apply an update rollup package, the update process updates the Outlook Web App files if they are required. Therefore, any customizations to the Logon.aspx file or to other Outlook Web App files are overwritten, and you must re-create the Outlook Web App customizations in Logon.aspx.